The present invention relates to a manually activated position indicator having electrical output signals and more particularly to such a position indicator having a plurality of adjacent electrodes.
Position indicators of this type are known which include a rotatable disc that can be adjusted by means of a rotary knob. Depending on whether only an incremental position setting, only an absolute position setting or a combination of these two types of position settings is desired, this disc may only be provided with one clock track, only one code indicating the absolute position, or with both types of markings, which are generally read optically. Another known position indicator of this type, which is also known by the term "mouse," includes two impulse generators in a housing that is moved by hand, which impulse generators are associated with directions of movement that run perpendicular to each other and generate a given number of impulses per unit of distance traveled.
Because of their movable parts, both known position indicators are expensive and susceptible to malfunction. Above all, the latter position indicator, which makes possible a position determination in two coordinates, cannot be used or can be used in only a limited manner, in an environment containing dirt, particularly on a dirty support.